The main barrier reducing outflow of aqueous humor in open angle glaucomas is the juxtacanalicular trabecular meshwork. The trabectome removes this pathophysiologically altered tissue by electroablation, thus allowing for the collector channels draining Schlemm's canal to directly communicate with the anterior chamber. In studies published so far, about 30% decrease of intraocular pressure and a simultaneous 42% reduction of pressure-lowering eyedrops could be achieved in primary and secondary open angle glaucomas. A clear cornea tunnel is used to advance the trabectome to the trabecular meshwork, leaving the conjunctiva unaffected. Hence minimally invasive chamber angle surgery using this device is in particular suitable for patients with an altered ocular surface. Lowering of intraocular pressure and reduction of needed topical medication seems to be distinct in pseudoexfoliative glaucoma. Surgery with the trabectome and phacoemulsification can easily be combined in one procedure. Using a minimally invasive approach, the complication profile of the trabectome is rather advantageous, not exceeding the general risks of globe-opening surgery. Ab-interno trabeculotomy is a safe and effective method for treatment of patients with primary or secondary open angle glaucomas and moderate target pressures.